Re: [v6ops] I-D Action: draft-colitti-v6ops-host-addr-availability-01.txt

Hi,

> -----Original Message-----
> From: v6ops [mailto:v6ops-bounces@ietf.org] On Behalf Of Andrew ?? Yourtchenko
> Sent: Tuesday, July 28, 2015 6:58 AM
> To: Gert Doering
> Cc: IPv6 Operations
> Subject: Re: [v6ops] I-D Action: draft-colitti-v6ops-host-addr-availability-01.txt
> 
> On 7/28/15, Gert Doering <gert@space.net> wrote:
> > Hi,
> >
> > On Mon, Jul 27, 2015 at 03:25:18PM +0200, Andrew ????  Yourtchenko wrote:
> >> The disjoint nature of IA_NA means a corresponding number of TCAM
> >> entries is required on L3 switches.
> >>
> >> A prefix, on the other hand, requires just an entry for the link-local
> >> of the host + an entry for the prefix. Regardless of the prefix
> >> length.
> >
> > All true.  But then you excercise pressure on the prefix allocation side
> > - instead of having "one /64 for that LAN segment, which is big enough
> > for arbitrary number of hosts" you end up with "a /52[-ish] per LAN segment
> > to cover DHCP-PD delegation to thousands of hosts".
> >
> > (Say, 1000 hosts, all doing DHCP-PD and requesting a single /64, you'd
> > need to provision at least a /54 per segment - which will increase your
> > prefix usage enormously)
> >
> > Is that what you want?
> 
> I did not look at it as a problem given that every mobile phone on
> IPv6 will already get a /64 per host, and the number of mobile phones
> is dramatically bigger than the number of fixed installations.

That is correct that /64 per host is what is being done for mobile phones.

Also, DHCPv6 PD has an advantage over SLAAC - there is no need for
DAD on the link over which the prefix is delegated, since the prefix is
not assigned to that link. And, the DHCPv6 server will ensure that
prefixes are uniquely assigned so that there is no duplication.

Thanks - Fred
fred.l.templin@boeing.com

> But I pulled that assumption more or less out of my thumb, based on
> observed anecdata, so would be happy to be proven wrong.
> 
> If we say we want to absolutely avoid NAT, then something has to give,
> and I don't know which tradeoff is a better one, both can be argued
> for and against. I think we might need both.
> 
> --a
> 
> 
> >
> > Gert Doering
> >         -- NetMaster
> > --
> > have you enabled IPv6 on something today...?
> >
> > SpaceNet AG                        Vorstand: Sebastian v. Bomhard
> > Joseph-Dollinger-Bogen 14          Aufsichtsratsvors.: A. Grundner-Culemann
> > D-80807 Muenchen                   HRB: 136055 (AG Muenchen)
> > Tel: +49 (0)89/32356-444           USt-IdNr.: DE813185279
> >
> 
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